If the system instrumentation support is enabled then the I/O package provides support for generating instrumentation records for various events within the general purpose I/O framework.
Instrumentation records will only be generated if the CYGIMP_IO_INSTRUMENTATION option is enabled, and then only if the relevant individual event code sub-options are also enabled. The default state is for all the instrumentation to be disabled. Some options will generate a lot of instrumentation records in a heavily loaded system and so care may need to be taken regarding the instrumentation that is enabled vs the instrumentation recording mechanism being used to avoid missing events. Depending on why the I/O framework instrumentation is being enabled (debugging, timing validation, etc.) the user can choose which events they wish to record by enabling the specific CDL options.